Aerorock, 10 LA Hydroponic Growing Medium. A fired-blown clay material that is sterile, lightweight that can used in hydroponics, blended with soils for improved aeration, or as decorative top dressing for container plants. Use it alone in hydroponics or try blending it with Coir or your favorite planting mix for superior aeration. Aerorock is a much better alternative to perlite, in that it wil... — Ships from Vancouver, WA and/or HF: Petaluma, CA, Santa Fe Springs, CA, Broomfield, CO, Fairless Hills, PA, Grand Prairie, TX, Medley, FL USA...more info.